Modular chains are typically designed to run in a guide as shown in various patents, e.g., U.S. Pat. Nos. 4,742,906; 4,805,764; and 5,036,969. In order to improve the running properties of the chains, various systems have been proposed for holding the chains down in their guide channel by means of magnetic forces. In most cases, permanent magnets are installed in the guide. The chain modules are typically constructed of ferromagnetic material to be dragged against the magnetic guide and thus, due in part to the magnetic forces, the chain modules do not vibrate or lift off when moving. The ferromagnetic properties of the chain modules can be achieved by producing the module completely from ferromagnetic steel, by using ferromagnetic hinge pins, or by adding ferromagnetic powder to the plastic resin used to produce the modules (U.S. Pat. No. 4,823,939).
One of the problems associated with the above described methods is the high manufacturing cost. The magnetic elements (permanent magnets) need to be incorporated into the guides either by installing them piece by piece into cavities provided in the guide bodies and securing them mechanically or by gluing and the like. Further, the magnets may create additional friction by holding the modules pressed into the guide channel. This additional friction can result in excessive abrasion leading to a shortening of the useful life of the chain.
There is also a need for holding down belt modules of the “bricklayed” variety including straight running and radius belts.
There are also applications for modular belts and chains where the need is to reduce the friction forces between the chain or modular belt and their guides or slider supports. The reduction of friction is of particular importance for radius belts and chains as well as for heavily loaded straight running conveyor belts. Since the friction between guides or supports and moving chains/belts is determined by the combination of their materials, the reduction of friction and also wear can only be achieved by optimal selection of these material combinations. In some cases, if acceptable, the guides and/or supports are lubricated to reduce the friction.
Accordingly, there is a need for an economic way to produce magnetic chain or belt modules for use with magnetic guides for holding the modules on the guide. Further, there is also a need for reducing the friction forces between chains or belt modules and guides or supports.